nah, it probably is just some shitty old wireless G adapter inside the computer, a wireless N or ac would probably work better. repeaters are quite expensive but that would also work. the dongle would probably be possible for like $15 - probably would have been the better option to start with. wireless-ac would definitely have no problem.
i was getting about 30% signal at 30 feet to a cheap tp-link dongle. i have a repeater and it went up to 70%. old wood door and steel reinforced concrete walls and i have 50% from the same spot with a mobile phone acting as my router. old phones can be good wifi dongles too. many people have them sitting around (i have two spare), just plug in the USB and you get a bit more scope to play with the position of it to get better signal. the only downside of the phones is having them constantly plugged in without rooting them to get charge control they can bloat up the battery and pose an eventual fire hazard.
to be honest, the better option for a mempool display would be a rooted android tablet with charge controller installed.
anyway, that might inspire some options to fix the problem. moving the router is another one too, it might just need to be a foot to the left and suddenly it's better.